Abstract

U-shaped development has been the subject of interest in the field of developmental psychology, for it is generally assumed to reveal the mechanism underlying developmental phenomena not easily provided by linear patterns. This study reviews various theoretical and empirical studies of U-shaped behavioral growth published at home and abroad during mainly the 1980s. This review is intended to answer some controversial questions based on the factual information contained in surveyed literature. The following facts were confirmed from the reviews. First, most data seem to support the observation that U-shaped development is a significant developmental phenomenon revealing changing developmental mechanism even though several studies suggest that it is a methodological artifact as some information processing theorists maintain. Second, U-shaped development has been proved to be a common occurrence observed in diverse areas of development such as perception, cognition, language, social cognition and social behavior. Third, a temporary drop in a fairly congruent age period is ovserved among different researchers and tasks in the same area of development. Fourth, in U-shaped development the high performance levels before and after a temporary drop reflect different developmental mechanisms rather than the same one. Fifth, despite a temporary drop in performance, U-shaped phenomena signify a continuous advance in competence, not reflective of a real regression in developmental process.